Waveguides served as a device for transmitting electromagnetic wave in microwave or visible light wave band are commonly included in electronic components such as thermally assisted magnetic heads in information storage devices.
In performing the thermally assisted magnetic writing, near field light is generally used for applying heat to a magnetic recording medium. In this technology, light propagating through a waveguide (guided light) is not directly applied to a plasmon generator, but the guided light is coupled to the plasmon generator through evanescent coupling, and surface plasmon polaritons generated on a surface of the plasmon generator are utilized.
As the waveguide is functioned as guiding light, thus a temperature rise of the surface of the writing element is occurred, and heat will be congregated on the surface of the waveguide or its neighbors to damage the elements. For solving this problem, people tries to study to improve the surface performance, by changing and improving the material of the waveguide, or adding a film on the waveguide, etc.
A conventional surface forming method is to form a film 104 to cover the end surface of the small area on the main portion 103, as shown in FIG. 1a-1c. Commonly, the photoresist film 101 covered on the front end surface (which is to be formed as an air bearing surface 10) of the writing element 100 is partly exposed by UV light 12 emitted to the front end surface directly. Concretely, this position to be removed must be aligned to the end surface of the small area on the main portion 103. Due to the UV light 12 is emitted to the front end surface of the writing element 100, from top to bottom, thus it's necessary to align the light 12 with the right position of the end surface of the main portion 103, so as to prevent the main portion 103 of the writing element being exposed. As a result, such a UV exposure process must be performed accurately and patiently, which leads to a time-consuming process for a plurality of writing elements to be machined. All appearance, it's inefficient to use this surface forming method to production in batches.
Thus it is desired to provide a surface forming method for electronic component, to overcome the drawbacks mentioned above.